Cardiometabolic Medicine: Development of a New Subspecialty

David R. Saxon; Cara Reiter-Brennan; Michael J. Blaha; Robert H. Eckel

Disclosures

J Clin Endocrinol Metab. 2020;105(7):2095-2104. 

In This Article

Development of the Field of Cardiometabolic Medicine

We, like other authors, believe in the development of the field of Cardiometabolic Medicine.[47,48] Other specialties such as palliative care and gerontology have grown out of a multiplicity of backgrounds in the face of a need for holistic care, and this concept could be applied to a cardiometabolic specialty.[49] To help fill the already mentioned gaps in care, the cardiometabolic physician will focus on the many aspects of how metabolic diseases relate to the primary and secondary prevention of CVD. For the most part this care will circumvent care typically provided by the endocrinologist and cardiologist. The primary care physician, either internist or family physician, will still direct the patient's overall health maintenance, provide urgent routine care, and request consultations from other specialists when appropriate, but they would do so in conjunction with the cardiometabolic physician who would be well positioned to deal with myriad complex metabolic and cardiovascular issues as they arise. Referrals and communication with other specialists would be a shared responsibility between the patient's primary care provider and their cardiometabolic physician.

Cardiometabolic Medicine Training Program

What would the training program for Cardiometabolic Medicine look like? After completion of a 2- or 3-year general internal medicine program, fellowship training in Cardiometabolic Medicine for most general internists would start immediately thereafter, primarily be a composite of endocrinology and cardiology, but would also incorporate salient aspects of hepatology, nephrology, obesity medicine, and nutrition/physical activity (lifestyle) training (Figure 2).

Figure 2.

Major Components of the field of Cardiometabolic Medicine.

The growth of the subspecialty would require support for development of training programs dedicated to the task at hand. Initially this would need to be a joint venture between endocrinology and cardiology within the context of their established fellowship training programs. This support could grow within institutions or from National Institutes of Health T32 training grants but would likely need funding from the multiplicity of pharmaceutical companies who relate to cardiometabolic diseases. As the need for this specialization may not be apparent to all, little may ensue in the short term. However, the growth of programs in gerontology may be exemplary. In 1965, the Older American's Act was passed in expectation of what was to ensue with regards to the health of the general population. Although courses in aging were in existence, gerontology training programs were not. Then in the 1970s the importance of aging-related science and medicine in developed countries followed and the need for training and education in geriatrics and gerontology gained momentum. Programs then developed not under the guidance of formally trained gerontologists but by internists and other subspecialists whose interest was devoted to older populations. This academic and clinical direction was not only motivated by diseases more frequently seen in elderly people but by inquiries about normal or physiological aging, an important part of the mission of the National Institute of Aging.

A more specific structure for a 3-year fellowship program in Cardiometabolic Medicine is outlined in Figure 3. The endocrine training component would focus on metabolic diseases and provide robust clinical experience in all forms of diabetes, obesity, lipid and lipoprotein disorders, and hypertension management. Other traditional aspects of endocrinology training—thyroid, pituitary, reproduction, metabolic bone disease, and calcium disorders—would not be included in the program. Specific clinical experience would include rotations through (1) diabetes clinics with the goal of developing expertise in basal-bolus insulin management, insulin infusion pumps, continuous glucose monitor, closed loop systems, and intensive insulin therapy (2); would include consultative time on inpatient glucose management teams (3); multidisciplinary obesity clinics with a focus on individualized lifestyle management of obesity, obesity pharmacotherapy, and training in referral to and postoperative management of patients undergoing bariatric (metabolic) surgery, nutrition therapy (ie, counseling, meal replacement programs), and exercise physiology; and[4] lipid clinics where the focus would be on learning how to manage complex patients with statin intolerance, moderate to severe hypertriglyceridemia, and genetic lipid and lipoprotein disorders including homozygous and heterozygous familial hypercholesterolemia, Tangier Disease, lecithin-cholesterol acyltransferase (LCAT) deficiency and other disorders with very low high-density lipoprotein cholesterol levels, and patients with elevations in lipoprotein (a).

Figure 3.

Proposed Structure of a 3-year program in Cardiometabolic Medicine.

The cardiology training portion of Cardiometabolic Medicine would focus on primary and secondary ASCVD prevention and evaluation. Rotations in cardiology would include inpatient cardiology (floor and cardiology consults), preventive cardiology clinic, interpretation of electrocardiography, cardiac rehabilitation, and cardiac imaging (echocardiography, stress testing, and coronary computed tomography).

In particular, training in cardiac imaging should focus on assessment of coronary atherosclerosis to guide decisions about intensity of cardiovascular risk reduction. International guidelines increasingly endorse coronary imaging in order to personalize risk assessment and optimize primary preventive care.[50,51] Therefore, a balanced approach to both the anatomical assessment and the functional assessment of atherosclerotic cardiovascular disease should be implemented (as opposed to traditional cardiology training which is commonly more focused on functional and interventional approaches). Computed tomography (CT) imaging has advanced as a reliable method to obtain information on severity of atherosclerosis. Trainees should be proficient in reading and interpreting coronary artery calcium scans, executed by noncontrast, cardiac gated CT. In addition, clinical experience should include basic coronary CT angiography interpretation of plaque burden, morphology, and vessel stenosis. With regard to functional testing, cardiac stress testing should be included with emphasis on fitness and symptom assessment. As resting transthoracic echocardiography is widely used to assess patients with suspect symptoms or structural heart disease, trainees should be adept in interpreting basic echocardiography. Transesophageal echocardiography, magnetic resonance imaging, and nuclear imaging would be outside of the scope of this proposed specialty.

Trainees would stay focused on cardiometabolic medicine and therefore would not do rotations in electrophysiology, interventional cardiology, advanced heart failure, or cardiac transplantation. Several months of time would be dedicated to management of severe hypertension (through a multispecialty resistant hypertension clinic) and in vascular medicine.

A key component of the training program would be intensive experience in all aspects of lifestyle management. Dedicated time would be spent obtaining expertise, often from nonphysicians, in advanced nutrition, exercise, and smoking cessation counseling. Given the likely future role of the cardiometabolic physician trainee as a leader of a multidisciplinary team, incorporation of dedicated leadership training within the fellowship would be an important component.

Clinically, the broad skill set of the cardiometabolic specialist would provide the possibility of having dual appointments in cardiology and endocrinology divisions in the academic setting. Cardiometabolic specialists would work primarily in outpatient clinics with a multidisciplinary team consisting of dietitians, certified diabetes care and educators, clinical pharmacists, and advanced practice providers, and would be well positioned to help train these individuals in certain aspects of high-risk cardiometabolic care. In larger healthcare systems, surveillance of comorbid chronic diseases through electronic health records could help target specific patients that would most benefit from referral to a Cardiometabolic Medicine specialist.

We envision that until formalized training programs are developed that many Cardiometabolic Medicine specialists will obtain jobs at academic or other highvolume centers and become integrated into established cardiology or endocrine practices. Careers that are science based would be encouraged with many new and exciting inquiries possible within basic, preclinical, clinical and population science, and public health/policy all available. Establishment of the field of Cardiometabolic Medicine would breed research ideas that would emerge and benefit from closer collaboration among interested disciplines.

Research Training in Cardiometabolic Medicine

Basic and preclinical research could relate to molecular and cellular mechanisms of any of the components of Cardiometabolic Medicine. Examples include basic mechanisms of the effect of insulin action on the genetic control of hepatic fatty acid and triglyceride metabolism, very low-density lipoprotein production and secretion, molecular mechanisms of resistant hypertension in animal models or the role of innate immunity in models of atherosclerosis propagation. Clinical research in humans could be directed towards understanding the mechanisms for transition from normal glucose tolerance to prediabetes to T2DM, approaching why higher levels of high-density lipoprotein cholesterol may fail to protect against ASCVD, and why patients with obesity are more likely to develop atrial fibrillation. Studies using populations need to comprehend why diverse populations of gender, socioeconomic status, race, and ethnicity experience different consequences of cardiometabolic diseases, apply genetics to expand the field of personalized medicine to cardiometabolic risk, and develop new strategies using real world evidence to implement randomized controlled trials so that that vulnerable populations can more readily receive appropriate, proven therapies.

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